Aggregate process for petroleum production

ABSTRACT

Water, hydrocarbons, and air are reacted together within a catalytic chamber to provide high temperatures, high-pressure products of reaction having increased percentage composition of hydrogen and carbon dioxide therein. A catalyst in the form of an alkali metal oxide or an alkaline earth metal oxide is carried to the reaction zone in the water stream, thereby providing the additional function of treating the water. The high temperature oxygen free gases are injected into a reservoir and contact the oil bearing formation thereof to increase the production of crude therefrom.

Ft ami United States Patent 2,871,942 2/1959 Garrisonetal....-.. 166/2602,973,812 3/1961 166/261X Walter A. Myrick, 111

MacSporran 10/1967 Lange..........

[21] Appl. No. [22] Filed May 19,1969 (45] Patented July 27, 1971Primary Examiner- Stephen J. Novosad Attorney Marcus L. Bates {54]AGGREGATE PROCESS FOR PETROLEUM PRODUCTION 1 6D F 10 Ch m "mug igs'ABSTRACT: Water, hydrocarbons, and air are reacted [52] US. togetherwithin a Catalytic chamber to provide h igh tempera- 166/250, 166/64tures, high-pressure products of reaction having increased 43/24percentage composition of hydrogen and carbon dioxide 166/272, therein.A catalyst in the form of an alkali metal oxide or an alv 256, 302, v 57kaline earth metal oxide is carried to the reaction zone in the waterstream, thereby providing the additional function of treating the water.The high temperature oxygen free gases are s11rm.c|................. so

[56} References Cited UNITED STATES PATENTS 2/1956Walter......................

injected into a reservoir and contact the oil bearing formation thereofto increase the production of crude therefrom.

PATENTED me? [an SHEET 1 OF 2 FIG. 2

m K Wm IR VI M R E m W BY MARCUS L. BATES PATENTED JUL27|97| 3,595,316

' sum 2 [1F 2 IN VIiN'I'OK WALTER A. MYRICK 111 m MARCUS L. BATESAGGREGATE PROCESS FOR PETROLEUM PRODUCTION BACKGROUND OF THE INVENTIONThe normal percentage recovery of liquid products from most petroleumreservoirs is between 30 percent and 40 percent, however, somedistillate fields yield as high as 50 percent and some low gravityfields less than percent. Hence, the majority of reservoirs contain morethan 60 percent of the original oil after they have been subjected tonormal production methods. It is for this reason that secondary recoveryoperations are being vigorously pursued by the petroleum industry. Someforms of secondary recovery systems include the use of steam flood,water flood, fire flood, stripping or gas purge, inert gas, and dilutionwash. Many low A.P.I. gravity oil fields exhibit low yields regardlessof the methods of production employed and most field still contain atleast 50 percent of the original liquid petroleum after application ofsecondary recovery methods thereto. The many theoretical advantages ofthe various secondary recovery processes have not been fully realized inmost installations because of the high cost of the original installationas well as the many mechanical and process problems encountered.

It is therefore desirable to incorporate the more successful features ofthe older secondary recovery processes into a simple unified systemwhile circumventing many of the imperfections and drawbacks inherent inthe older methods, along with improved selection of temperature andpressure ranges so as to control the combustion process in a manner toprovide a mixture of gases having chemical and physical properties whichare highly desirable for adding displacement energy to the naturalunderground reservoirs, and in producing changes in the physicalproperties of the petroleum oils as well as the production formation tothereby facilitate increased recovery of the contained oils in a mannerwhich has heretofore been unknown.

SUMMARY OF THE INVENTION This invention embraces a method of secondaryrecovery of petroleum oils from formations by the provision of acontrolled combustion process which entails the production of mixedgases by the reaction ofa hydrocarbon, including natural gas, along withair, and water. The reaction occurs within a reactor at relatively highpressure and temperature and in the presence of an alkali metal oxide oran alkaline earth metal oxide catalyst to thereby provide combustionproducts having chemical and physical properties which are highlydesirable for adding displacement energy to underground reservoirs aswell as changing the physical properties of both the petroleum oils andthe production formation in a manner which facilitates increasedrecovery of the contained oils. The catalyst also serves as a watertreating chemical, and has advantages when carried downhole into the oilbearing formation.

It is therefore a primary object of the present invention to provide anew catalytic reaction process for producing products of combustion foruse downhole in an oil well.

Another object of the present invention is the provision ofa method ofincreasing the H and CO content of products of combustion.

Still another object of the present invention is the provision of animproved method of secondary recovery of petroleum oils from oil bearingformations.

A further object of the present invention is the provision of a catalystwhich is carried into a combustion reaction by means ofa water stream.

Another object is the provision of products of combustion which treat anoil reservoir in a new and different manner.

A further object of the present invention is the provision of a reactorfor converting fuel, air, and water into products of combustion.

The above objects are attained in accordance with the present inventionby the provision of a new process which is carried out essentially asset forth in the above abstract and summary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow sheet n the form ofaschematical drawing or diagram which sets forth a generalization of themethod of the present invention;

FIG. 2 is a cross-sectional detail of a hydrocarbon reactor which can beused in conjunction with the method taught in FIG. 1; and withadditional flow control means and conduits being schematicallyrepresented therein;

FIG. 5 is a cross-sectional view taken along line 3-3 of FIG.

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a cross-sectional view taken along lie 5-5 of FIG. 2; and

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In carrying out themethod of the present invention, air, a hydrocarbon such as natural gas,and water, respectively, are flow conducted through conduits 10, 12, and14, respectively, and into a hydrocarbon reactor. An alkali metal or analkaline earth metal oxide, including potassium,,and magnesium, andspecifically potassium sulfite and potassium carbonate, is transferredat 18 into a water treatment tank 16 prior to the treated water beingflow conducted into the hydrocarbon reactor 20. The air, gas, and waterreact together within the combustion zone of the reactor and emerge asoff-gases at 22 where they are subsequently flow conducted through awellhead 24 and downhole as seen at 25 to the production zone.

The air, fuel, and water enter into chemical reaction in the presence ofone or more of the before-mentioned catalyst at elevated temperaturesand pressures, for example, 700 p.s.i.g. and 750 F. The catalyst servesthe dual purpose of increasing the oxidation of the reactants to H andCO as well as reducing the corrosion and collection of scale which wouldotherwise occur throughout the system, as well as consuming and reactingwith the dissolved oxygen which is present in the injection water, aswill be described in greater detail later on.

Looking now to the details of FIG. 2, in conjunction with the remainingfigures, the hydrocarbon reactor 20 is seen to have an externalhigh-pressure shell 26 which terminates in an inner flange 27, with theflange being bolted to outer blind flange 28, and with central flangemember 29 being sandwiched therebetween.

An igniter 30 has an ignition means 31 associated therewith and isoperably disposed within the reactor where it is controllably extendedinto close proximity of the combustion area by means of adjustmenthandle 32. Housing 33 forms a support for the igniter control means.

Gas conduit 34 flow connects a regulated or controlled gas supply 12with a gas nozzle 35. Burner 36 is spaced apart from andcircumferentially encloses the gas nozzle therein, thereby leaving theillustrated annulus therebetween.

Air conduit 37 interconnects controlled air supply 10 with atoroidallike air passageway which serves as a preheater, as will bebetter appreciated when discussed in greater detail later on.

Reaction zone 38 is defined by the high temperature insulation 39 whichis bonded to inner shell 40 with the inner shell being connected to thebefore-mentioned central flange 29. The inner shell together with theinside peripheral wall 42 of the outer shell cooperates together to forman annulus 41 therebetween. A series of nozzles, 43 and 44, are spacedapart from one another and flow communicate with annulus 41. Sleeve 45is affixed to the lowermost portion of the inner shell of the reactorwhere it slidably receives reduced portion 47 of outlet tubing 46 in atelescoping manner to thereby provide an expansion joint.

Looking again now to the details of FIGS. 2 through 5, it

stock because of its low cost and ease of handling, however, otherhydrocarbon gases including propane, butane, as well as any suitableliquid hydrocarbon can be used to advantage in the present invention.The quantity of gas consumed by the will be noted that the center flangesupports the inner shell reactor varies in accordance with the operatingconditions, and also serves as a means ofcontrolling the flow of waterand and assuming a lO/l air to fuel ratio with a flow rate of 100catalyst into the reactor. Water inlet passageways 14' are flow mcf. ofnatural gas being consumed, l35 barrels of treated connected to thebefore-mentioned source of water 14, and water will be required. Thewater must be clarified and each of the passageways inwardly terminatesin a circumpreferably contains less than l600 p.p.m.dissolved solids.The ferentially extending concavity or grooved passageway 50, sodiumchloride content as well as the dissolved silica should with the lowerwall surface of the concavity receiving a mulnot be excessively high.The injection pressure, that is, the tiplicity of apertures in the formof spaced apart drilled pressure within the reactor or at the wellheadis generally passageways each of which flow Communicate the Waterdetennined by the type and thickness of the reservoir formapp y with theannulus l 5 tion and is limited in accordance with the thickness of the8 to demhs of the wmldal passageway, overburden. However, it is desiredto maintain the temperaahd in Particular 2 in Conjunction With the airture between 500750 F. with the pressure being controlled inlet 37 isseen to be connected to annulus 53 at a point adat 700 p.s.i.g. wherepermissible. The following examples of jacent to the illustrated baffle52 which provides a circular flow rates are typical of mostinstallations of the process:

Bbl. Natural water H2, CO1, Air flow, gas feed per mole mole Temp,Pressure, m.c.f. m.c. A/F ratio day percent percent F. p.s.i.g

flow path to the illustrated inlet located on the opposite side of Asseen in the above examples which set forth two different the baffle soas to provide a continuous flow path for the air airflow rates, when theA/F ratio is maintained within the into chamber 54. Chamber 54 conductsthe airflow through desired perimeters the hydrogen content and COcontent inport 54' and into the annulus formed between burner 36 andcrease as the A/F ratio decreases. The formation of H is ingas nozzle 35to thereby enable air and gas to be admixed at creased while theformation of CO also increases but at a the free depending terminal endof the burner. The cylindrical relatively slower rate for the reasonthat the production of CO housing 60 is spaced apart from cylindricalhousing so as to is largely avoi e due to the Water reaction. When theprovide a dead air space therebetween. 4O hydrocarbon feed rate isincreased to a value which exceeds Looking now to the flow controldetails as set forth in the the above desired perimeters, the hydrogenand CO content schematical portion of FIG. 2, there is disclosed thebeforedecrease due to the formation of excessive carbon monoxidementioned water and catalyst flow passageway 14, having flow and freecarbon. When the A/F ratio is increased within the measuring orificeassembly 62 controllably connected to the desired Perimeters h hyd ogeand 2 Content i recording ratio flow controller 63 which in turn iscontrollably ififi ih connected to and actuates a motor control valve64, thereby An increase in the flow rate of injection water lowers theenabling the flow rates to be carefully maintained within a temperatureof the off-gases and tends to more readily quench predetermined range ofvalues. The ratio flow controller is the reaction, which increases theformation of H and connected to flow measuring orifice 66 and actuatesthe decreases the formation of CO. motor control valve 68 of the airsupply. Pressure controller The optimum conditions for natural gas(1,000 B.t'.u./ft.") 74 resets ratio flow controller 63 so as to controlthe flow rate are set forth under column three of the above table. Theacof water and air to thereby maintainapreset pressure. tual mass flowrate of effluent gases can be adjusted in ac- There is schematicallyshown arecording temperature concordance with the number of wellsundergoing treatment. troller 70 which is pneumatically connected to thecontrol Generally the gas consumption will be 46,000--l40,000 valve 72,and which actuates the valve in accordance with a scf./D for one reactorwhich is flow connected to several injecsignal received from temperaturetransmitter 76. Additionally, tion wells. g V H w the recordingtemperature controller records the P and The treatment chemicals whichare added to the injection flow fate sensed at 74 and respectivelY waterfor corrosion control serve as a catalyst to increase the Pneumaticallymanua ly opera e Vent Valve 77 Provides 8 oxidation of the carbonmonoxide to carbon dioxide and to Safety bypass for Venting the gases tothe atmosphere Pheu" 6O enhance the formation of hydrogen. The catalystis an alkali maticahy manually Operated flow valve 78 Provicles a metaloxide or an alkaline earth metal oxide,ora combination means forinterrupting flow the Wellhead Check Valve 80 of the two, and preferablyis added to the raw water as potassi- P' now of Products and gases fromthe weiiheadum carbonate and potassium sulfite, although magnesium car-Electri lly atituated Solenoid Valves 82, 83, 85, and 86 bonates andsulfites are also acceptable catalysts. The catalyst are actuated byswitches (not shown) associated with recordi an gent whi h i selectedfrom the following group of ing temperature controller 70, so as toenable emergency shutmaterials: potassium, lithium, rubidium, cesium,magnesium, down Of th system, n to vent the m n t0 the calcium,strontium, and barium, wherein the agent is in the mosphere. form of abisulfate bicarbonate, sulfite, carbonate, or a nitrite, Relie valves 83n 89 are automatically actuated at Any combination of these substancescan be used, however, it elevated pressures which exceed the designedoperating presi preferred to use a mixture comprised of potassium sureof the systembonate and potassium sulflte so as to realize the maximumadvantage of the catalyst since this form of the catalyst offersOPERATION some form of treatment throughout the system.

The catalysts are added to the feed water, as for example,

In operation, natural gas is preferred as the reactor feed potassiumbisulfite, and as potassium carbonate for pH control. Potassium sulfiteand potassium bicarbonate can also be used where deemed desirable. Whereremoval of dissolved oxygen from the feed water is required, thecatalyst can be introduced as potassium nitrite as well as the sulfiteas an oxygen scavenger.

As a more specific example of catalyst introduction into the feed water,and assuming the metal potassium to be available for use, sufficientsulfite or nitrite is added to remove the free oxygen from the feedwater. Potassium bicarbonate and potassium carbonate is then added inorder to balance the pH. The total weight percent of potassium mustprovide sufficient potassium ions to promote the desired reaction withinthe combustion chamber. This requirement will vary between and 100 ppm.potassium ions in the feed water, with 30 ppm. being considered optimum.

Assuming that the feed water has been chemically treated by thecatalysts, and flowing through conduit 14, its rate of flow will bemaintained constant by the ratio flow controller as the water enterspassageway 14'. The water flows through the grooved passageway, throughthe apertures 51, and through the annulus 41 where it enters the reactorat 43, 44, and through the slip joint between sleeve 54 and 47, thusmaintaining the shell 40 within its structural limitations so far asregards the temperature and pressure existing within combustion chamber38. As the water, along with the catalyst, enters the combustionchamber, it is a least partially in the form of steam and accordinglythe potassium carbonate, for example, will now be converted to potassiumoxide, which is the required form of the catalyst in order to promote orinfluence the combustion reaction to be driven in a direction whichenhances the formation of CO and H and minimizes the presence ofO andCO.

Motor valve 68 controls the rate of flow of air as it enters inlet 37,flows about the path formed by annulus 53, through the illustrated portadjacent the baffle, into the chamber 54, where it continues to flowabout the igniter and burner and then enters the port 54' and flows intothe burner annulus where the air then mixes with the natural gas orother suitable hydrocarbon from nozzle 35. The igniter 31, when it isnot in use, is maintained in the retracted position clear of the area ofintense heat within the combustion chamber.

Generally, the system is controlled as follows: the temperaturetransmitter 76 forms the primary control means for controlling thecombustion process. The transmitter provides a signal which is sensed bythe recording temperature controller 7, which is pneumatically connectedto the control valve 72 in order to actuate the valve in accordance withthe signal. This enables the temperature at 70 to be selected, whereuponthe temperature will thereafter be maintained within a predeterminedlimit.

The pressure controller 74 resets the ratio flow controller 63 inaccordance with the pressure sensed at 74, and maintains the flow ratioof water and air within a predetermined range of values. The pressurecontroller is connected back to the recording temperature controller forrecording purposes, as well as enabling actuation of thebefore-mentioned pressure limit switches. Also associated with therecording temperature controller are temperature limit switchesconnected to sense the temperature at transmitter 76. The pressure andtemperature limit switches are connected to valves 82 through 86 toprovide automatic shutdown in the event the temperature or pressure ofthe system should diverge from a predetermined range or limit ofvalues.

As the water, hydrocarbons, and air are burned or reacted togetherwithin the reaction chamber of the reactor, a multitude of complexreactions occur, the details of which are unnecessary for a clearunderstanding of the invention, but which may be summarized as follows:

C,,H H O O, N, H O CO H N C0 trace of NO and N0 The'catalyst, togetherwith the reactants exit at outlet tubing 22 along with a significantquantity of potassium sulflte, which becomes available as an oxygenscavenging agent as the gases flow through the remainder of theequipment.

The catalyst, in addition to removing free oxygen from the feed water,enhances the combustion of CO to CO by causing the dissociated oxygenfrom the water molecule to combine with the CO molecule, which in turnleaves the dissociated hydrogen from the water molecule free torecombine with itself, thereby increasing the molecular hydrogen contentof the effluent gases to a value between the limits of l percent to 6percent, depending upon the flow rates of the air, gas, and water. Thewater of combustion together with the excess feed water remains in thegaseous phase, and is referred to herein as superheated steam.

The superheated steam is available to increase the temperature of theformation downhole in the well to thereby reduce the viscosity andspecific gravity of the petroleum contained within the reservoir whichin turn reduces the oils resistance to flow. The increased temperaturecoupled with the carbon 1 dioxide which is adsorbed in the condensateenables the water to preferentially wet or to be adsorbed on the surfaceof the sand or production formation, thereby displacing oil therefrom.ln paraffinic oil the increased temperature increases the solubility ofthe paraffin in the formation oils thus reducing the tendency of theparaffin to plug the well bores. The Co also dissolves in the oil toreduce its viscosity as well as its specific gravity, while some of theCO combines with water to form carbonic acid which reacts with lime,dolomites, and other calcareous formations to produce water solublesalts, thereby increasing the porosity of the formation. The carbonatedwater droplets are more easily pushed through the formation by thenitrogen and accordingly tends to wash the oil from the formation. Thecarbonic acid lowers the ph of the formation fluids thereby lowering thesurface tension of the oil which enables the oil to be washed ordisplaced from the surface of the sand.

The nitrogen increases the reservoir pressure and drives the condensedsteam through the formation so as to produce a washing action. The smallamount of nitrogen oxides which are produced in the reactor is convertedto nitrous and nitric acids in the production formation and reacts withcalcareous formations to produce soluble salts. The acids also producefree hydrogen ions which are available to displace alkaline earthelements from the lattice structure of the clays, thus effectivelyincreasing the porosity of the formation.

The potassium oxide is converted back to potassium carbonate due to thepresence of CO downhole, which enables reaction with various alkalineearths to occur; calcareous deposits for example, to give apotassium-magnesium carbonate, which is soluble in water, thus enablingthe calcareous rock deposits to be solubilized, to thereby effectivelyincrease the porosity of the formation.

Hydrogen produced by the reactor serves in a mannersimilar to nitrogenbut more importantly it produces a reducing atmosphere which tends toreduce corrosion of the metal equipment. Dissolved hydrogen tends toreduce oil viscosity and specific gravity. The hydrogen is readilydispersed through the formation because of its small molecular size.

As will now be evident to those skilled in the art, the water injectionwithin the reactor is utilized to produce superheated steam which is theprimary carrier of heat into the formation; to react with carbonmonoxide and hydrocarbons to produce hydrogen and CO which improves theoverall efficiency of the operation by producing a larger volume of gasper unit of fuel consumed; to control the reaction temperature as wellas to cool the reactor and the reaction products; and as the solutionmedium for carrying the catalyst into the reactor where the catalyst canpromote production of hydrogen and CO from hydrocarbons and CO.

The increased pressure in the formation caused by the injection gasestends to reduce the flashing of the light ends from the petroleum whichwould otherwise be caused by the increased temperature within theformation. The light ends (C C C and C are maintained in solution andcontribute to reduction of viscosity and specific gravity The wells areplaced on 3- to lO-day cycles, depending upon the formation depth andcharacteristics. At the end ofeach injection period, upon initialproduction. dissolved salts will be returned to the wellhead where theycan be accumulated for subsequent disposal.

It is necessary to insulate the upper portion of the production tubingto prevent damage to the well head, cement, and casing.

The cost of operation and installation is low, the apparatus lendsitself to automatic control, and many wells heretofore considereddepleted by secondary recovery methods can actually be revitalized bythe instant invention, and hence in many cases the present inventionconstitutes a tertiary recovery system rather than a secondary recoverysystem.

lclaim:

1. An improved method of recovering hydrocarbons from a well bore whichis connected to a subterranean natural reservoir by treating thereservoir according to the following steps:

1. treating water with an agent selected from the group consisting ofpotassium, lithium, rubidium, cesium, magnesium, calcium, strontium, andbarium, wherein the agent is in the form of either a bisulfite,bicarbonate, sulfite, carbonate, or a nitrite;

2. reacting the treated water of step (1) by combusting the water with ahydrocarbon in the presence of air to produce a gaseous productcomprised of superheated steam, the agent, and flue gases;

. maintaining the product obtained in step (2) at a temperature whichavoids condensation of the superheated steam within the injection tubingof the well bore;

4. flowing the product into the subterranean reservoir.

2. The method of claim 1 wherein the gaseous products are maintainedabove 500 F. and p.s.i. at the reactor outlet.

3 The method of claim 1 wherein the agent is comprised of a mixture ofpotassium carbonate and potassium sulfite.

4. The method of claim 1 wherein the agent is comprised of potassiumnitrite, and the air/fuel ratio is maintained between the limits of 8/1and l2/l.

5. The method of claim I wherein the agent is comprised of potassiumbicarbonate, and the air/fuel ratio is between the limits of8/l and12/1.

6. The method of claim 1 wherein the agent is magnesium and is in theform of a nitrite or a carbonate.

7. The method of claim 1 wherein the agent is magnesium nitrite and theair/fuel is 8/1 to l2/l. 4

8. An improved method of recovering hydrocarbons from a well bore whichis connected to a subterranean natural reservoir by treating thereservoir according to the following steps:

1. treating water with an agent selected from the group consisting ofpotassium and magnesium wherein the agent is in the form of a carbonate,sulfite, or nitrite;

2. reacting the treated water of step (i) by combusting the water i witha hydrocarbon in the presence of air to produce a gaseous productcomprised of superheated steam, the agent, and flue gases;

. flowing the product obtained in step (2) into the subterraneanreservoir by using an injection tubing within a well bore connected tothe reservoir;

4. maintaining the product obtained in step (2) at a temperature whichavoids condensation of the superheated steam within the injection tubingof the well bore.

9. The method of claim 8 wherein the agent is comprised of a mixture ofpotassium carbonate and potassium sulfite.

10. The method of claim 8 wherein the agent is magnesium and is in theform of a nitrite or a carbonate.

1. An improved method of recovering hydrocarbons from a well bore whichis connected to a subterranean natural reservoir by treating thereservoir according to the following steps:
 1. treating water with anagent selected from the group consisting of potassium, lithium,rubidium, cesium, magnesium, calcium, strontium, and barium, wherein theagent is in the form of either a bisulfite, bicarbonate, sulfite,carbonate, or a nitrite;
 2. reacting the treated water of step (1) bycombusting the water with a hydrocarbon in the presence of air toproduce a gaseous product comprised of superheated steam, the agent, andflue gases;
 3. maintaining the product obtained in step (2) at atemperature which avoids condensation of the superheated steam withinthe injection tubing of the well bore;
 4. flowing the product into thesubterranean reservoir.
 2. reacting the treated water of step (1) bycombusting the water with a hydrocarbon in the presence of air toproduce a gaseous product comprised of superheated steam, the agent, andflue gases;
 2. The method of claim 1 wherein the gaseous products aremaintained above 500* F. and 170 p.s.i. at the reactor outlet. 2.reacting the treated water of step (1) by combusting the water with ahydrocarbon in the presence of air to produce a gaseous productcomprised of superheated steam, the agent, and flue gases;
 3. flowingthe product obtained in step (2) into the subterranean reservoir byusing an injection tubing within a well bore connected to the reservoir;3. The method of claim 1 wherein the agent is comprised of a mixture ofpotassium carbonate and potassium sulfite.
 3. maintaining the productobtained in step (2) at a temperature which avoids condensation of thesuperheated steam within the injection tubing of the well bore; 4.flowing the product into the subterranean reservoir.
 4. The method ofclaim 1 wherein the agent is comprised of potassium nitrite, and theair/fuel ratio is maintained between the limits of 8/1 and 12/1. 4.maintaining the product obtained in step (2) at a temperature whichavoids condensation of the superheated steam within the injection tubingof the well bore.
 5. The method of claim 1 wherein the agent iscomprised of potassium bicarbonate, and the air/fuel ratio is betweenthe limits of 8/1 and 12/1.
 6. The method of claim 1 wherein the agentis magnesium and is in the form of a nitrite or a carbonate.
 7. Themethod of claim 1 wherein the agent is magnesium nitrite and theair/fuel is 8/1 to 12/1.
 8. An improved method of recoveringhydrocarbons from a well bore which is connected to a subterraneannatural reservoir by treating the reservoir according to the followingsteps:
 9. The method of claim 8 wherein the agent is comprised of amixture of potassium carbonate and potassium sulfite.
 10. The method ofclaim 8 wherein the agent is magnesium and is in the form of a nitriteor a carbonate.